
#include <unistd.h>
#include <sys/types.h>
main ()
{
    pid_t pid;
    printf("hello!\n");
    pid=fork();
    if (pid < 0)
        printf("error in fork!");
    else if (pid == 0)
        printf("i am the child process, my process id is %d\n ",getpid());
    else
        printf("i am the parent process, my process id is %d\n",getpid());
    printf("bye!\n");
}